> The reference states that: > The returned coordinates (dst) are normalized to be in range [0, 1].

> But it returns numbers like 3,5 or -0,7 ....

No, it probably just means that your geometry is outside the view volume, and is then projected outside the viewport. (0,0) is the lower left corner of the viewport, (1,1) is the upper right corner.

Fetching the correct SbViewVolume is not always that easy BTW. You can use SoCamera::getViewVolume(), but you need to adjust for the viewport mapping. See <URL:http://doc.coin3d.org/Coin/classSoCamera.html#a3> for more information.